Could this still retain the mach 3.0 supersonic terminal sprint since it's a YJ-18 variant? If so, combining both stealth and supersonic terminal would make it very lethal.
I doubt it, the profile of this thing looks very much like a standard stealthy AshM/LACM.
Being a YJ-18 "variant" I suspect is mostly in name only, perhaps having some common components from it.
But in the same way Club AShM and Kalibr LACM are both part of the 3M54 family (as well as a bunch of other weapons including ASROC esque types), both the standard YJ-18 (surface/sub launched) AShM and this subsonic stealthy AShM/LACM are in the same "YJ-18 family". A bit silly but oh well.